Peresters of oxo-substitiuted polyperoxycarboxylic acids



United States Patent PERESTERS 0F OXO-SUBSTITUTED POLY- PEROXYCARBOXYLIC ACIDS Frank H. Dickey, Berkeley, Calif'., assignor to Shell Development Company, Emeryville, Califi, a corporation of Delaware No Drawing. Application January 18, 1952, Serial No. 267,203

13 Claims. (Cl. 260-453) 7 This invention relates to a new class of organic compounds. More particularly, the invention relates to a ,new class of organic peresters, and to their utilization, particularly as polymerization catalysts.

Specifically, the invention provides new organic compounds having unexpected superior properties as polymerization catalysts comprising peresters, and particu-. larly the tertiary-alkyl peresters, of oxo-substituted polyperoxypolycarboxylic acids wherein the oxo group in the acid molecule is in the alpha or beta position relative to one of the peroxy carboxyl groups.

This application is a continuation-in-part of my application Ser. No. 715,132, filed December 9, 1946, now abandoned.

It is known that vinyl monomers, such as vinyl chloride, may be polymerized in the presence of peroxide catalysts, such as benzoyl peroxide, hydrogen peroxide, tert-butyl perbenzoate and ditertiary-butyl .diperoxy: ph'thalate. While these catalysts are satisfactory for polymerizing the monomers on a small scale, their use in pro.- ducing polymers for many commercial applications leaves much to be desired. The known catalysts are, for example, quite ineffective at low temperatures .and the reaction must be accomplished at a relatively high temperature to obtain a satisfactory polymerization rate. The use of high temperatures in the polymerization of these monomers is undesirable as it produces polymers having low molecular weights, poor color and formstability at room temperature, and inferior mechanical properties.

It is an object of the invention, therefore, to provide a new class of polymerization catalysts. It is a further object to provide a new class of perester catalysts that are effective at low reaction temperatures. .It .is a .further object to provide novel organic peresters that can produce, at a fast rate, polymers having excellent physical properties. It is a further object to provide polymerization catalysts that are particularly effective in a slightly alkaline medium. It is a further object to provide novel catalysts that are effective in bulk, suspension or emulsion systems. It is a further object to provide a new class of organic peresters having unique and valuable properties. Other objects and advantages of the invention will be apparent from the following detailed description thereof.

It has now been discovered that these and other objects may be accomplished by the novel compounds of the invention comprising peresters, and particularly the tertiary-alkyl peresters, of oxo-substituted polyperoxypolycarboxlic acids wherein the oxo group in .the acid molecule is in the alpha or beta position relative to one of the peroxy carboxyl groups. These peresters areJparticularly superior catalysts for the polymerization of vinyl monomers as they are ableto initiate polymerization at a very fast rate even at the relatively low reaction temperatures. Thus, while the conventional peroxide catalysts described above show little activity at temperatures below about 30 -C., the aforedescribed special group of peresters are quite active at temperatures as low as 20 C. to --10 C. and form high yields of polymers in that temperature range in a very short period. The polymerization of vinyl chloride with the known catalysts, for example, generally requires from 40 to 72 hours to complete at the higher temperatures, but the same degree of polymerization may be accomplished with the above-described novel peresters in thesurpris- ,ingly short period of .15 -minutes vat room temperature Patented Jan. 4, 1955 ICC using a much smaller amount of catalyst. In addition, it has been found that the polymers produced by the use of theseparticular, catalysts possess superior properties even though they are formed at a very fast rate.

The high activity of these peresters at the low reaction temperatures can be chiefly attributed to the unique combination of having the oxo group in the alpha or beta position relative to one of "the perester groups. While the relationship between the oxo group in these positions and the perester group is not definitely understood, it does endow the compounds with unexpected activity, particularly when the compounds are utilized in a slightly alkaline medium. Other peresters which do not have the oxo group and the perester group in these particular positions, such as di-tertiary butyl diperoxysuccinate, ditertiary butyl diperoxyphthalate and tertiary butyl perbenzoate, do not possess this unexpected activity as shown in the experiments reported in the examples at the end of the specification.

The novel peresters of the invention require special methods of preparation as described hereinafter, but for clarity they will be described herein and in the appended claims as being theoretically derived from a polyperoxycarboxylic acid and a monohydric alcohol. 'The novel compounds may be theoretically obtained by ester-if ying (1) a polyperoxycarboxylic acid having an oxo group, i. e., a V

group, in their molecule in the alpha or beta position relative to one of the peroxy carboxyl groups, with (2) a monohydric alcohol. The term polyperoxypolycarboxylic acid refers to those acids possessing a plurality, and preferably from 2 to.4 percarboxyl groups, i. e.,

groups. These acids may be aliphatic, aromatic, alicyclic or heterocyelic and may be saturated or unsaturated. The essential oxo group in the acid molecule may be present in one of the said percarboxyl groups, such as in the case of diperoxyoxalic acid and diperoxymalonic acid, or may be present in a keto group, carboxyl group, acyl radical, i. e., a

radical, or ester radical, i. e., a

radical. If the acid contains an acyl radical, the said radical may be derived from any carboxylic acid, but is preferably derived from .a monocarboxylic acid such as the aliphatic monocarboxlic acids as acetic acid,butyric acid, valeric acid, caproic acid, cyclohexanoic acid, acrylic acid, methacrylic acid, 3,4,4-trimethylhexanoic acid, 2- ethylhexanoic acid, pelargonic acid, stearic acid, lauric acid, and cyclopentanoic'acid, and the aromatic acids, such as benzoic acid, ,isopropylbenzoic acid, toluic acid, chlorobenzoic acid, and vinyl ,benzoic acid. If the acids contain simple ester radicals, the said radicals may be obtained by the esterification of one or more of the carboxyl groups in the acid molecule with any type of alcohol, such as saturated and unsaturated, aliphatic and alicyclic alcohols, phenols, and the like, as methyl alcohol, ethyl alcohol, butyl alcohol, amyl alcohol, octyl alcohol, decanol, tetradecanol, allyl alcohol, methallyl alcohol, cyclohexanol, cyclohexenol, phenol, benzyl alcohol, chlorobutanol, and cyanohexenol.

The above-described oxo-substituted polyperoxycarboxylic ,acids may be exemplified by .the following: diperoxyoxalic acid, diperoxymalonic acid, diperoxybutylmalonic acid, diperoxydecylmalonic acid, diperoxydodecylmalonic acid, alpha-acetyldiperoxymalonic acid, alphabutyryldiperoxysuccinic acid, alpha-benzoyldiperoxyadipic acid, alpha-acetyltriperoxy-1,5,10-dodecanetricarboxylic acid, alpha-acrylyldiperoxyglutaric acid, alphaoleoyldiperoxysuberic acid, alpha-succinyldiperoxyglutaconic acid, alpha-carbomethoxydiperoxysuccinic acid, alpha-carboethoxydiperoxyadipic acid, toxydiperoxyglutaconic acid, alpha-carbohexoxydiperoxyhydromuconic acid, alpha-carbodecoxytriperoxy-1,4,6- octanetricarboxylic acid, alpha-keto-diperoxysuccinic acid, alpha-keto-diperoxyglutaric acid, alpha-keto-diperoxysebacic acid, alpha-keto-diperoxyglutaconic acid, betaketo-diperoxydodecanedioic acid, beta-keto-diperoxy-4- octenedioic acid, beta-keto-diperoxyhendecanedioic acid, and beta,delta-diketo-diperoxydodecanedioic acid.

Preferred oxo-substituted peroxycarboxylic acids used in the theoretical production of the novel peresters comprise diperoxyoxalic acid, diperoxymalonic acid, the diperoxyalkylmalonic acids, the alpha-keto-substituted diperoxydicarboxylic acids wherein the two percarboxyl groups are separated by at least one carbon atom, the beta-keto-substituted diperoxydicarboxylic acids wherein the two percarboxyl groups are separated by at least two carbon atoms, the alpha-acyl substituted diperoxydicarboxylic acids wherein the two percarboxyl groups are separated by at least one carbon atom, and the alpha-carboalkoxy substituted diperoxydicarboxylic acids wherein the tWo percarboxyl groups are separated by at least one carbon atom, the alpha or beta positions referred to above being in relation to one of the percarboxyl groups.

Particularly preferred acids are the members of the group consisting of (1) diperoxymalonic acid, (2) diperoxyoxalic acid, (3) the diperoxyalkylmalonic acids wherein the alkyl radical contains from 1 to 14 carbon atoms, (4) the alpha-keto-substituted diperoxyalkanedioic acids containing from 3 to 12 carbon atoms and having the two percarboxyl groups separated by at least one carbon atom, (5) the beta-keto-substituted diperoxyalkanedioic acids containing from 4 to 12 carbon atoms and having the two percarboxyl groups separated by at least two carbon atoms, (6) the alpha-alkylcarbonyl substituted diperoxyalkanedioic acids containing from 1 to 8 carbon atoms in the alkylcarbonyl radical and from 3 to 12 carbon atoms in the rest of the acid molecule and having the two percarboxyl groups separated by at least one carbon atom, and (7) the alpha-carboalkoxy substituted diperoxyalkanedioic acids containing from 1 to 8 carbon atoms in the carboalkoxy radical and from 3 to 12 carbon atoms in the rest of the acid molecule and having the two percarboxyl groups separated by at least one carbon atom. The term alkylcarbony radical used in the above description refers to the radicals wherein R is an alkyl radical.

The alcohol portion of the novel peresters of the invention may be derived from any monohydric alcohol but is preferably derived from the tertiary monohydric alcohols, i. e., alcohols possessing a tertiary carbon atom, preferably attached directly to the hydroxyl group. Examples of such alcohols are tertiary butanol, tertiary hexanol, tertiary octanol, tertiary decanol, diphenylethylcarbinol, triphenylcarbinol, phenyldibutylcarbinol, chlorophenylethylbutylcarbinol, cyclohexyldiphenylcarbinol, and cyclopentyldirnethylcarbinol. Particularly preferred alcohols are the tertiary monohydric alcohols containing from 4 to 18 carbon atoms. Especially preferred are the tertiary alkanols containing from 4 to carbon atoms.

The novel peresters of the invention are theoretically obtained by esterifying at least two of the percarboxyl groups of the above-described polyperoxycarboxylic acids with one or more of the above-described alcohols. Examples of the novel peresters of the invention are ditertiary butyl diperoxyoxalate, di-tertiary butyl diperoxy malonate, di-tertiary butyl diperoxydecylmalonate, tertiary butyl tertiary amyl diperoxyoctylmalonate, di-tertiary hexyl alpha-ketodiperoxysuccinate, di-(dimethylbenzyl) alpha-ketodiperoxyadipate, di-tertiary octyl alphaketodiperoxyglutaconate, di-tertiary hexyl beta-ketodiperoxysebacate, di-tertiary nonyl beta-ketodiperoxybrassylate, di-(dibutylbenzyl) alpha-acetyldiperoxysuccinate, di-(triphenylcarbinyl) alpha-acrylyldiperoxyglutarate, di-tertiary nonyl alpha-oleoyldiperoxysuccinate, di- (dibutylbenzyl) alpha-succinyldiperoxyglutaconate, di-ter tiary octyl alpha-carboethoxydiperoxyadipate, di-tertiary butyl a]pha-carbobutoxydiperoxysuccinate, di-tertiary amyl alpha-carbohexoxydiperoxy-4-octenedioate, and dinonyl alpha-carbohexoxydiperoxydodecanedioate.

alpha-carbobu The preferred peresters of the invention, i. e., those theoretically derived from the above-described preferred acids and the preferred tertiary monohydric alcohols containing from 4 to 18 carbon atoms, may be exemplified by di-tertiary butyl diperoxyoxalate, di-tertiary dodecyl diperoxymalonate, di-tertiary butyl diperoxydodecylmalonate, di-tertiary nonyl alpha-ketodiperoxysuccinate, di-(alpha,alpha-dimethylbenzyl) alpha acetyldiperoxysuccinate, di-(alpha,alpha-dibutylbenzyl) alpha-carboethoxydiperoxysuccinate, and di-tertiary butyl alphaacetyldiperoxyfumarate.

The above-described peresters cannot be obtained by direct esterification of a peracid with an alcohol as the hydroxy group of the water of esterification must come from the acid and not the alcohol. Special methods must, therefore, be employed for the preparation of these particular compounds. The more preferred method comprises reacting a hydroperoxide with the desired acyl halide in the presence of an alkali.

The preferred hydroperoxides to be used in this process are those derived from the above-described tertiary monohydric alcohols, such as tertiary-butyl hydroperoxide, tertiary-amyl hydroperoxide, diphenyl-methylcarbinyl hydroperoxide, 5-butyl-5-hydroperoxy-decane, dirnethylbenzyl hydroperoxide, cyclohexyldiphenylcarbinyl hydroperoxide, and cyclopentyldimethylcarbinyl hydroperoxide.

The acyl halides used in the process may be exem-' plified by oxalyl chloride, malonyl chloride, methylmalonyl chloride, dodecylmalonyl chloride, alpha-acetylsuccinyl chloride, alpha-butyrylsuccinyl chloride, alphacarboethoxysuccinyl chloride, alpha-acrylyladipyl chloride, alpha-ketoglutaconyl chloride, beta-ketopimelyl chloride, beta-ketosebacyl chloride, and alpha-benzoylsuccinyl chloride.

The alkali employed in the process includes pyridine, sodium or potassium bicarbonate, or sodium hydroxide. A sufiicient amount of the alkali should be used to insure that the reaction mixture will be alkaline throughout the reaction, i. e., an excess over that necessary to react with the acyl halide.

The reaction may be conducted in the presence or absence of solvents or diluents. In the case of the more viscous peroxides, inert solvents, such as carbon tetrachloride, heptane, or octane, may advantageously be employed.

The proportions of hydroperoxide and acyl halide employed in the reaction may vary over a considerable range. It is generally desirable to react the acyl halide with at least a chemical equivalent amount of the hydroperoxide. The expression chemical equivalent amount as employed throughout the specification and claims refers to the amount of hydroperoxide required to furnish approximately one peroxide group for every acyl group to be reacted. Preferably the acyl halide and hydroperoxide are reacted in chemical equivalent ratios of 1:1 to 1:15, respectively.

The reaction is ordinarily conducted in the liquid phase in a vessel equipped with suitable heating or cooling means. Preferably, the reaction is conducted in a batch operation with the hydroperoxide, alkali and solvent, if any, being added first and the acyl halide being added in small quantities over a period of time. The reaction temperature will vary somewhat with the reactants. In some instances the reaction proceeds at a rapid rate at temperatures as low or lower than 0 C., while in other cases it may be necessary to raise the temperature to 80 C., or above to obtain a satisfactory reaction rate. Preferred temperatures range from 0' C. to C. Atmospheric, superatmospheric, or subatmospheric pressures may be utilized as desired.

The peresters may be recovered from the reaction mixture by any suitable means, such as precipitation, extraction, filtration, fractional distillation, and the like.

The novel peresters of the invention possess many unusual properties which make them particularly useful and valuable in industry. They are valuable, for example, as bleaching agents for flour, etc., as sterilizing agents or components for antiseptic compositions, as driers for oils as linseed and tung oil, and as catalysts for free radical chain reactions, such as the addition of polyhalogenated hydrocarbons to olefins, and various telomerization reactions as disclosed in U. S. Patents No. 2,438,021, No. 2,418,832, and No. 2,440,801.

The novel peresters are especially valuable as catalysts for the polymerization of vinyl monomers. The exass-w pression "vinyl monomers? includes all those organic compoundscontaining at least one CH2=C group. in their'molecul'e. 1 Examples {of these monomers are styrene, alpha-methyl'styrene, dichlorostyrene, vinyl. naphthalene, vinylphenol, acrylic acid and the alpha-alkyl substituted acrylic acids; the esters of these unsaturated. acids, such as' methyl acryl'ate, methyl methacrylate butyl methacrylate; and propyl acrylate;:the vinylidene halides, such as'vinylidene' chloride, vinylidene bromide and vinylidene fluoride; the vinylesters of the inorganic acids, such as the halogemacids andhyd'rocyanic' acid, as'vin'yl chloride, vinyl bromide, acrylonitrile, and metha'cryloni'trile; the vinyl} esters of the'monocarboxyl-ic acids, such as vinyl acetate, vinyl chlorofaceta'te, vinyl, benzoat'e, vinyl valerate,"andvinyl eaproate; the vinyl esters of the polycarboxylic acids, such asdivinyl-succinate, divinyladipate, vinyl allylphthalate,,,vinyl' methallyl' p'imelate, and vinyl methyl glutarate; the vinyl esters of the unsaturated acids, such as. vinyl acrylate, vinyl crotonate, and vinyl methacryl'ate; the vinyl ethers; such as vinyl ethylether, vinyl butyl ether, and vinyl allyl ether; the vinyl ketones, such as'vinylbutylket'one, and vinyl. ethyl ketone; and" the allyl derivatives, such as allyl acetate, allyl butyrate, diallyl phthalate', diallyl adiphate, methallyl' propionate, allylchloride methallyl chloride, ally acrylat'e, and methallyl methacryla'te.

The peresters are also effective as catalysts for the copolymerization of the above-described compounds with other types of polymerizable organic compounds, particula rly those containing at least one ethylenic linkage, sucl'r, asethylene', the saturated esters of theunsaturat'ed itiiids, such as diethylmaleate, dibutyl crotonate, and the e V Polymerization of the vinyl monomers in the presence of the novel peresters may be accomplished by'avariety offmethods. The polymerization may be accomplished in bulk, in a solvent solution or in an aqueous emulsion or suspension. The peresters usually display their maximum catalytic activity in a mildly alkaline medium so it is usually desirable to accomplish the polymerization in an aqueous emulsion where the desired pH maybe easily maintained. In this preferred method the material to be polymerizedisadded' to a mixture containing water, an emulsifying agent, a mildly alkaline pH adjuster, and the monoperester catalyst, and the resulting mixture maintained at the desired temperature and pressure.

Emulsifying agents that may be employed in the preferred. process: include the soaps, such as sodium and potassium myristate, laurate, palmitate, oleate, stearate, rosinateandhydroabietategthe alkali metalalkyl or alkylene sulfates, such. as sodium lauryl sulfate, potassium stearyl sulfate; the alkali metal alkyl or. alkylene sulfonates, such as sodium. lauryl sulfonates, potassium stearyl .sulfori'ate, and sodium cetyl sulfate; sulfonated mineral oil, as well as the ammonium salts thereof; and salts of high amines like lauryl. aminehydrochloride, and stearyl amine hydrobromide. The amount of theem'u'l'sifying agent employed will generally vary between about 0.1%.. and 6% by weight of themonorner, preferably between 0.1% and 2% by weight of the monomer.

The desiredalkalinity may be maintained by the addition of alkalinepH adjusters, such as trisodium phosphate, sodium carbonate, sodiumbicarbonate, tetrasodium pyrophosphate, disodium hydrogen phosphate and calcium carbonate.

The temperature employed in the polymerization may vary over a. considerable range. The advantages of using thenovel peresters as catalysts are more evident, however, when the relatively low temperatures are employed. The use of temperatures as low or lower than -10 C. gives very satisfactory polymerization rates and produces polymers having the desired superior physical properties. Preferred temperatures range from C. to 50 C. Almospheric, superatmospheric or subatmospheric pressures may be employed as desired.

The polymers formed during the above-described polymerization process may be recovered from the polymerization medium by conventional means, such as addition electrolytes, solvents, freezing, dehydration, and the The resulting polymers are substantially colorless products possessing relatively high molecular weights. Elasticized specimens of the polymers possess excellent 'color and increased tensile-strength and flexibility and may bedtilized for, a Variety of commercial applications; such as the formation of rigid plastic: articles; ofivarious shapes and sizes, surface coating: compositions, -:imp1:eg n&tin3: agents,fand=the like. t 1 1 I t To illustrate the manner in: which: the: invention may becarried outsthe followingexamp'l'es are: given; 'It 'inito' be:- understood however, that the examples are: forthezpun pose of illustration and the invention is nottto beregardeds as limited to any ofthe: specific conditions citedrtheneina Unless otherwise specifiedt parts. described. in the examples are parts by weight.

In order tov conserve. space in. some of the. tables. shown in the following examples, the peresters have been described'only-with' the prefix per instead of peroxy. Thus; di-tert-butyl diperoxymalonate has sometimes been referred to as di-tert-butyldipermalonate; It should-thusbe understood that the :compounds referred: to-hereinby' the names containing the prefixper are the same'compounds as those given the same name' but with the prefix T y Example 1 Seven parts (0.05 mole) of 'malonylchloride was added" dropwise over a period of about 30' minutes to a' stirred solution composed initially of 1.08 parts (0.12 mole-)1 of anhydrous tertiary-butyl hydroperoxide and 8 parts (0.1 mole) of pyridine in about IOOparts' of petroleum ether, The temperature of the solution during the'additibn wasmaintained 'betw'eeni 5 Qi and 1 056. by immersing'the rea'ctidnve'sseli in an ice hath-L After all the 'acid' chloride was added, the ice bath was removed"and-thestirring continued for- 30- minutes. The water-soluble constituents were removed from the petroleum ether solution by extraction with eight- -part portions of water. The product was isolated by cooling the petroleum ether solution to the temperature of Dry Ice forone hour and. then: decanting the ether. The product was a pale yellow liquid having a slight peroxidic odor. Analysis of this material indicated it'was: d'i-tertia'ry-butyl diperox-ymal'onate. R-. I. N!-20/D"1.4356. 4 1 Y Found Theory Percent Carbon i 53. 3 Percent Hydrogen S 1 M.W..(as oxidizing agent towardHI in acetic acid). 248

Amount of Polymeri- Yicldoi Catalyst Catalyst zation Pol'ymer, '(PPHMP Time, hrs Percent 1. Di-tertiary-butyl' diperoxy- .5 1 85.

malonate. t 1 2. Di tertiary -butyl diperoxy- 0.25 1 100.

mal'onate. 3. Di tertiary-but'yl' diperoxy- 5 23. 5 'Negligible phthalate. i amount. 4. Di-tertiary-butyl diperoxy- 0.25 24 'sucei'nat'e. 5. Benzoyl peroxide 4 77' 8'1. 6. Diaeetyl peroxide 2 56 78. 7. Tart-butyl perbenzoate 2 46 27.

fBlHM=parts'per 100 parts-of-monomer.

1, 38nd 4=4Q0; water, 1 part-1 sodium lauryl sulfate (SLS), 0.5 part trisodlumphosphate.

2'=400 water-I part SLS', .25 part NaHSOz.

- 5=210 parts water,,2 parts SLS.

6 and 7 =300 parts water, 2 parts SLS.

A comparison of the above polymerization times and yields clearly indicates the unexpected increase in rate of polymerlzation that is obtained by using the novel oxosubstituted peresters overthe known peroxide type catalysts and other peresters, such. as di-tertiary butyl peroxysuccmate and di-tertiary-butyl diperoxyphthalate, which do not have the oxo group in the critical alpha or beta 88 positions.--

(1)) The high rate of reaction that is obtained with the novel peresters at the lower temperatures is shown in the following experiment: Three separate aqueous mixtures were prepared by adding about 100 parts of vinyl chloride Example 11 A solution containing 4.4 parts (0.05 mole) oxalvl chloride in 15 parts of petroleum ether was added with cooling and stirring to 75 parts of a petroleum ether soto water containing a dispersing or emulsifying agent. t The catalysts listed below were added in the indicated L23: g i i g g gf g e g g g g i g gfggig 9! to each the separate mlxiurets the mlxtllre was continued for about 5 minutes after the addition was mamtamed at P1YmenZat1Qntm! and yleld completed. At that time, 50 parts of water was added of polymer obtamed m each ease are given m the table and the solution shaken causing the formation of two below: 10 phases. The phases were separated and the upper phase was washed again with 50 parts of water and dried over 0 t 1 t Antglllnttof Polyng t rigileld of anhydcrlous islodium sulfate. Thedsolvent lwas egapolt lateld a Y5 a a Y8 1 Ym T1 all an a w ite crystalline peroxi e was 0 taine na (PPHWI T me,l1lS. Percent 15 i indicated that it was di-tertiary-butyl diperoxyoxalate. -gij'g'jggmgiggggfifigg 3'22 2 3:- The di-tertiary-butyl diperoxyoxalate produced above a: Di-tert-bui l di eror suec'iiti 1 n i is able to initiate polymerization of vinyl monomers, such a amount as v1nyl chloride and methyl methacrylate at a very fast *J diperoxyphthal' 24 rate at temperatures as low as C. At 20 C. a sys- 20 tem containing 100 parts of vinyl chloride, 400 parts of PPHM artspermopartsofmonomer water, 1 part sodium lauryl sulfate and 0.5 part triso- 1, 3 and 4 460 parts water,2parts Aerrsol OT (dioctyl sull'osucclnate). Chum phosphate and part dl'tertlary'butyl dlperoxy' 2=400water,lpartSLS,and0.5parttrlsodinmphosphate. l iz r v of pq yn ovter 8 z ggg g arge as a pro uce rom a s1m1ar sys em a though the Polymer was plodueed at a very fast 25 containing 0.25 part di-tertiary-butyl diperoxysuccinate rate in experiments 1 and 2 shown in the table above, the durin the same period products still have very good physical properties. Some of g the properties of the polymer formed in experiment 2 are E l 111 shown m the table below' Seven parts of dodecylmalonyl chloride was added dropwise over a pieriod ofi abcgus minlutesfto 2i] stiirred Tensile Ultimate solution com ose initia o mo e 0 an y rous weight strength Elmgatim 100%M0du1us tertiary-butyl hydroperoxi le and 9 parts of pyridine in 100 parts of petroleum ether. The temperature of the about 143,000 2,340 P- 05% 1,820 p. s. 1. solution during the addition was maintained between 5 and 10 C. by immersing the reaction vessel in an ice bath. After all the acid chloride was added, the ice (6) supenomypf Povel oxoisubstltuted F bath was removed and the stirring continued for 30 bulk pelymenzanen shown the followmg minutes. The water-soluble constituents were removed expenment: About 1 Parts of methyhmethaerylate and from the petroleum ether solution by extracting with styrene e Placed In separate tubes Wlth 1 Part of e 40 eight 100 part portions of water. The product was isolyst deserlbed. below 9 set of tubes was placed 1 lated by cooling the petroleum ether solution to the temroom m l i l at 25 o and anoiher Set Placed perature of Dry Ice for one hour and then decanting the mom mamtauted at The tune taken. for each ether. The product was a crystalline solid. Analysis Sample to attain l fl t Polymer eoneemratlon to of the material showed it to be di-tertiary-butyl diperoxycome non-flowing 1s mdtcated below: dodecylmalonate Settings? Time Found Theory Monomer Catalyst 0, Percent 66.1 66.3 5 0- C- H, Per 10.9 10.6

Benzoylpemxide 24 8 The di-tertiary-butyl diperoxydodecylmalonate pro- Methyl -iEiflgfiffiilgfffig'gfg gfimg;; duced above shows high activity in polymerizing vinyl S gel'ltztyltpieroxlgeuni 1 38 5 monomers, such as styrene, methyl methacrylate and e f 'f'f" lhi t...fiblttgiingffiididiseii1 2 21 rylonitnle, at low temperatures.

Example IV (d) The superiority of the novel catalysts of the in- A s t contalmng Parts of b qp y vention in a slightly alkaline medium is shown in the h l' 1T1 Petroleum ether 15 added with cooling and following experiment: Methyl methacrylate, methacrylorr 1ng to 150 Parts Petroleum ether Solution C011- nitrile and styrene were polymerized in separate mildly talnlflg 11 R f 0f y butyl PYS R and 10 alkaline aqueous emulsions in the presence of the perester Parts of PYE Coollng and i g 1S Contlmled catalyst indicated below. The polymerization mixture ab011t 5 mlnutes after the aflidltlon 15 completedin each case was made up of 100 parts monomer, 0.5 60 that tlme, 50 parts of water is added and the solution pal-t catalyst, 1 part sodium lauryl lf t 5 Part shaken causing the formation of two phases. The phases dium bicarbonate and 300 parts water. The polymerare separated and the upper phase washed and dried over ization was conducted at 43 C. The results obtained in anhydrous su1mm- Solvent eYaPofated each case are indicated in the bl b l and the resulting product ldentified as di-tertrary-butyl 7o beta-keto-diperoxypimelate.

The di-tertiary-butyl beta-ketodiperoxypimelate pro- Percent duced above shows high activity in polymerizing vinyl Monomer Catalyst Time, 1 d chloride and styrene, particularly when employed in an (hrs) meme alkaline medium.

Example V 'i t ilitii tieiii fii't'e 2 About 005 mole of alpha a et 1 c'n 1 hl 'd -cysuc1ycor1e1s Methyl methacrylate L' g dwelmal' 94 added dropwise over a period of about 40 minutes to a lienztyltpiaroxigm t g Stirred solution1 ionjlposed intiallydog 10.1 mole of arhye u y per eum em rous tert-amy y roperoxi e an mo e of pyri ine Methacrybmme dipermalo' 23 in about l50 parts of petroleum ether. The temperature Benzoylperoxide 1.0 1 of the solution during the addition is maintained be- SWFBM {Tert'butyl pelibemoate tween 5 C. and 10 C. by immersing the flask in an Di-tert-butyldlpermelom- 93 ice bath. After all the acid chloride is added, the bath 8 is removed and the stirring continued for about one hour.

The water-soluble components are removed by extracting with ten 50 part portions of water. The product, ditertiary-amyl alpha-acetyldineroxysuccinate, is isolated by cooling the petroleum ether solution to the temperature of Dry Ice and then decanting the ether.

The di-tertiary-amyl alpha-acetyldiperoxysuccinate produced above is particularly active as a polymerization catalyst at the low reaction temperatures for monomers, such as vinyl chloride, styrene, and methyl methacrylate.

Peresters having related properties may be obtained by replacing the alpha-acetylsuccinyl chloride in the above process with equivalent amounts of each of the following chlorides: alpha-butyryladipyl chloride, alpha-benzoylglutaryl chloride and alpha-acetylglutaconyl chloride.

Example VI To a suspension containing 33 parts (0.1 mole) of 53% sodium alpha,alpha-dimethylbenzyl hydroperoxide in petroleum ether is added 7 parts (0.05 mole) of malonyl chloride. The mixture is allowed to stand at room temperature for one hour with occasional stirring. At the end of this time the solution is washed with water and with two successive portions of aqueous sodium bicarbonate. The solution is dried over anhydrous sodium sulfate and the solvent removed by evaporation at re duced pressure to yield di-(alpha,alpha-dimethylbenzyl) diperoxymalonate.

Peresters having related properties may be obtained by replacing the malonyl chloride in the above process with equivalent amounts of each of the following chlorides: oxalyl chloride, octylmalonyl chloride, and butylmalonyl chloride.

Example VII About 10.55 part (0.05 mole) of alpha-carbomethoxysuccinyl chloride is added dropwise to a stirred solution composed initially of 12.48 (0.12 mole) parts of anhydrous tert-amyl hydroperoxide and 10 parts of pyridine in about 150 parts of petroleum ether. The temperature of the mixture was maintained at a low level by immersing the vessel in an ice bath. After all the chloride is added, the ice bath is removed and the stirring continued for about 30 minutes. The water-soluble constituents are removed from the petroleum ether solution by extracting with eight 100 part portions of water. The product, di-tertiary-amyl alpha-carbomethoxydiperoxysuccinate, is isolated by cooling the petroleum ether solution to the temperature of Dry Ice for one hour and then decanting the ether.

The di-tertiary amyl alpha-carbomethoxydiperoxysuccinate produced above may be used to polymerize vinyl chloride, styrene, acrylonitrile, and methacrylonitri e.

Peresters having related properties may be obtained by replacing the alpha-carbomethoxysuccinyl chloride in the above process with equivalent amounts of each of the following chlorides: alpha-carboethoxysuccinyl chloride, alpha-carbobutoxyadipyl chloride and alpha-carbobutoxysuccinyl chloride.

I claim as my invention:

1. A perester of an oxo-substituted polyperoxycarboxylic acid having an oxo group in the acid molecule not more than one carbon atom removed from one of the peroxycarboxyl groups.

2. A perester of a beta-keto substituted diperoxydicarhoxylic acid wherein the keto group is in the beta position relative to one of the peroxycarboxyl groups and the two peroxycarboxyl groups are separated by at least two carbon atoms.

3. A perester of an alpha-alkylcarbonyl substituted diperoxydicarboxylic acid wherein the alkylcarbonyl group is in the alpha position relative to one of the peroxycarboxyl groups and the two peroxycarboxyl groups are separated by at least one carbon atom.

4. A perester of an alpha-carboalkoxy substituted diperoxydicarboxylic acid wherein the carboalkoxy group is in the alpha position relative to one of the peroxycarboxyl groups and the two peroxycarboxyl groups are separated by at least one carbon atom.

5. A tertiary alkyl perester of an oxo-substituted polyperoxycarboxylic acid having an oxo group in the acid molecule not more than one carbon atom removed from one of the peroxycarboxyl groups and containing from 3 to 15 carbon atoms.

6. A compound of the group consisting of (l) ditertiary alkyl diperoxyoxalate, (2) ditertiary alkyl diperoxymalonate, (3) ditertiary alkyl diperoxyalkylmalonate, (4) tertiary alkyl diperesters of alpha-keto substituted diperoxyalkanedioic acids wherein the two peroxycarboxyl groups are separated by at least one carbon atom, (5) tertiary alkyl diperesters of beta-keto substituted diperoxyalkanedioic acids wherein the two peroxycarboxyl groups are separated by at least two carbon atoms, (6) tertiary alkyl diperesters of alpha-alkylcarbonyl substituted diperoxyalkanedioic acids wherein the two peroxycarboXyl groups are separated by at least one carbon atom, and (7) tertiary alkyl diperesters of alpha-carboalkoxy substituted diperoxyalkanedioic acids wherein the two peroxycarboxyl groups are separated by at least one carbon atom, the alpha and beta'terms used above being in relation to one of the peroxycarboxyl groups.

7. A ditertiary alkyl diperoxyoxalate.

8. A ditertiary alkyl diperoxymalonate.

9. Ditertiary butyl beta-keto-diperoxyglutarate.

10. Ditertiary butyl alpha-acetyl-diperoxysuccinate.

11. Ditertiary butyl alpha-carboethoxy-diperoxysuccinate.

12. Ditertiary butyl diperoxymalonate.

l3. Ditertiary butyl diperoxyoxalate.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A PERESTER OF AN OXO-SUBSTITUTED POLYPEROXYCARBOXYLIC ACID HAVING AN OXO GROUP IN THE ACID MOLECULE NOT MORE THAN ONE CARBON ATOM REMOVED FROM ONE OF THE PEROXYCARBOXYL GROUPS. 